Discard the outer celery stalks. Carefully wash the remaining, wipe in a cloth and chop finely into a salad bowl. Grind the walnuts coarsely. Add to the celery. Chill until the moment you serve. In a deep dish, mash the blue cheese with a fork, mix in the brandy. Use this cream as for a mustard. Salt, pepper, thin with the oil and the vinegar. To serve, pour the sauce onto the celery, stir and eat immediately.
